1 Gluszkowski M. 2006, Socio- and Psycholinguistic Aspects of Minority Languages Evolution. The Polish Old Believers Case – „Acta Universitatis Siauliensis” 2/2006, pp. 62-74 Michal Gluszkowski, Institute of Slavonic Languages Nicolaus Copernicus University of Toruń, Poland Socio- and Psycholinguistic Aspects of Evolution of Minority Languages in the EU: the Polish Old Believers’ Case Key words: Old Believers, Minorities, Migrations, Endangered languages, Socio- and psycholinguistics, Interfrence, Social amalgamation The main aim of this paper is to show the relationship between sociological and psychological factors and the evolution of minority languages. It is based on the results of a research project on the Old Believers (starovery, staroobr’adtsy) community near Augustów in north-eastern Poland. The research in question was performed by the scientific workers of Slavic Languages Institute at Nicolaus Copernicus University of Toruń. The first observations made by this research group, were presented in the 1970’s. There were also other research centers interested in the Old Believers, but nowadays the University of Toruń is the only one, which has continuous contact with the Old Believers community near Augustów. The history of the Old Believers began in Russia in 1652, when the Patriarch Nikon introduced a number of reforms to their rituals. Some of the followers refused to accept the changes, including the new direction of processions (counter-sunwise instead of sunwise), the sign of the Cross made with three instead of two fingers and revision of sacred texts. Although these reforms may appear trivial to contemporary people, they had begun the disobedience of a part of the Orthodox Church. Those worshippers, who did not endorse Nikon’s reforms, where officially deprived of church and civil rights at the synod of 1666. This was also the beginning of a schism in the Russian Orthodox Church (raskol). While the innovations were supported by Tsar Alexey Mikhaylovitch and his successors, the anti-reformists were severely persecuted, punished and even sentenced to death, both by church and state authorities. As a result, a large number of the Old Believers decided to live in exile – off the beaten track in Russia or in other countries, especially  Commonwealth of Poland and Lithuania and later also Bulgaria, USA, Canada and others. The first Old Believers had settled in Poland in the end of the 17 th century. In the beginning, there were several villages founded at the eastern frontier (present Ukraine, Belarus, Lithuania), where the Old Believers were granted land and freedom of religious practices by Polish landowners. Due to the fact that they were constantly displaced by tsar’s soldiers and most of their main centers were destroyed several times, the Old Believers moved to other Polish regions – the eastern part of